Reassign an event emitter in NodeJS

Question

I'm using the MQTT npm module. When fires the myMqttObj.on('close',...) event I call myMqttObj.end() and then reassign it with a new connection:

 myMqttObj= mqtt.connect(....)

In this way all the previous myMqttObj.on() methods are listening on the new emitter. All this works great.

Now I'm trying to create my own method to create a new MQTT connection with the same npm module. I want only to hide the MQTT connection parameter calling a custom method with a simple string as a parameter:

var mySDK= require('./mySDK');
mySDK.mqttConnect("input",function(_inMqtt){
    if(_inMqtt!=null){
        inMqtt=_inMqtt;  //inMqtt is a global variable

        inMqtt.on('connect', function() {
           //do something here
        });

        inMqtt.on('close', function() {
            inMqtt.end();
            mySDK.mqttConnect("input",function(_inMqtt){
                inMqtt=_inMqtt;  //this assignment to the same Client object doesn't work
            });
        });
});

the mqttConnect method simply call the mqtt.connect method and return the Client object.

I expect that all the inMqtt.on() function are now listening on the new Client object, instead no event is catched. What's the problem?